Atmospherically-responsive device.



N. HOFSTAD.

ATMOSPHERICALLY RESPONSIVE DEVICE. APPLICATION FILED AUG. I2, ISIB.

Patented NV. 5,1918.

IIIIIIIIIII UNITED sTATEs PATENT oEEIoE.

NELS HOFS'IAD, OF CHICAGO, ILLINOIS, ASSIGNOR TO JOHNSON SERVICE COMPANY, A

CORPORATION OF .WISCONSIN ATMQSPHERICALLY-RESPONSIVE DEVICE.

To all lwhom t may concern:

, State of Illinois, have invented certain new -and useful Improvements in Atmospherically-Responsive Devices, of which .the following is a full, true, and exact description, reference being had to the accompanying drawings, forming part of this specification.

The present invention relates to atmospherically responsive devicesv such as are used in the heating, Ventilating and air conditioning arts, in performing various operationsin response to changes in the condition of the atmosphere. Such devices include instruments responsive to temperature changes, Vcalled thermostats, and instruments responsive to humidity changes, called humidity regulators. has to do principally with the simplification of the structure of such devices. In such devices, air under pressure is usually employed as an actuating medium. The air commonly acts upon a diaphragm which cooperates with valves and passages toA supply i mechanlsm, as desired. The air supply pasair to the working point and to cut it o, as may be required by the atmospheric changes. The air under pressure is received bythe instrument from a suitable source of supply and controlled in its passage to a suitable delivery passage and the work. A valve controlling an opening between the receiving and delivery passages operates to supply or cut off the air under pressure and at the same time close or open an exhaust from the delivery passage. One object of my invention is toperform these necessary functions by an instrument having only one diaphragm. Another object is to simplify prior structuresby. rendering more of the parts xed and immovable and thereby simplifying the construction. This latter ob'-y ject applies especially tothe exhaust passage and its control. These various objects and features of the invention will bel more fully understood upon reference tothe full detail description taken in connection with the' accompanying drawings, while the scope of the invention will be pointed out in the appended claims.`

In said drawings: Figure 1 is a front elevation of a temperature responsive instrument constructed accordancel with the. present invention; Fig. 2 is a side elevation Specication of Letters Patent.

The invention Patented N ov. 5 1918.

Application led August 12, 1918. Serial N o. 249,486.

of the same, parts being shown in section taken on a plane indicated by the line 2-2 of Fig. l; Fig. 3 is a central vertical sectiGn of the same, the plane of section being indicated by the line 3-3 of Fig. l; Fig. 4 is a section of portion of the instrument illustrating the restrictin needle valve and associated .passages by w ich the supply of air to the diaphragm is controlled, the plane of section being indicated by the line 4 4 of Fig. l; Fig. 5 is a partial sectional elev vation of a humidity responsive elen luit Wlnch may be used in place of the temperature responsive element 'of the other figures;

and Fig. 6 is a general view of the thermo-- stat, or temperature responsive instrument, shown in operative relation to a compressor and an air pressure motor. Throughout these views like characters refer to like parts.

Referring to the drawings in detail, and more particularly at iirst to the general view of Fig. 6, the thermostat A is positioned between the source of compressed air supply, here shown as a compressor B, and the work, here an air pressure motor Cwhich may be used to operate a valve, damper, or other sage from the compressor C to the instrument A is provided by the pipe 10, while the deliverypassage is provided by the pipe 11. The first of these pipes, namely pipe 10, communicates with the elongated recess 12 in the upper body portion 13 of the frame of the thermostat, and the latter, that is pipe 11, communicates with the smaller recess 14. These pipe connections are commonly made through a mounting late of the type illustrated in United States atent No. 1,109,993 to C. F. Johnson, granted Sept. 8, 1914. 4The screw openingsl 15 and 16 in the body portion 13 of the instrument are provided for this purpose. But such connections ma be made in any suitable way.

With t e pipeslO and 11 thus connected, the supply pipe 10 communicates through recess 12 wlth a passage 17 terminating in a through recessv 14 with a passage 19 terminating in a delivery passage or chamber 20. An intermediate opening 21 connects the chambers 18 and 20. The opening 21 extends through the wall 22 and is provided with'a valve seat 23. A valve 24coperates with the seat 23 to open and close theintermediate opening 21. The stem of the valve 24 extends through the opening 21 and 1s provided at its forward end with a nut 25 which bears against the leai` spring 26. The stem of the valve extends through an opening in the center of the spring 26 and the nut is screwed on to the end of the stem. The outer ends of the spring 26 bear against the face of the wall 22. The construction of these parts is such that normally the spring 26 holds the valve 24 closed upon its seat 23 and air from the supply chamber 18 cannot pass to the delivery chamber 2O and out through the passage 19 and pipe 11 to the motor C. But it will be seen that if the valve 24 be moved against the tension of the spring 26, then the passage 21 will be opened so as to allow the passage of compressed air through the delivery pipe 11 to the work. To bring about this Amovement of valve 24 against the tension of spring 26, the instrument is provided with a diaphragm 27.

The diaphragm 27, which is composed of any suitable flexible substance, preferably patent leather, forms the forward wall of the delivery chamber 20. It is secured at its periphery to an annular projection 28 by means of a covering cap 29 and securing screws 30. The cap 29 is cut away on its inner surface so as to provide a chamber 31 to which air may be supplied or from which it may be exhausted, to control the movements of the diaphragm 27. Normally there is a slight clearance between the diaphragm and the end of the stem of valve 24. There is also a similar cle-arance between the dia phragm 27 and the adjacent end of fixed exhaust tube 32 which provides a fixed and immovable exhaust opening between the delivery chamber 20 and the atmosphere. Vhenever the diaphragm 27 is moved so as to engage the stem of valve 24, it also closes the exhaust passage through tube 32, since the adjacent end of the exhaust opening lies in the path of travel of the diaphragm. 0n the other hand, whenever diaphragm 27 is moved away from valve 24, exhaust port 32 is opened. In this way the diaphragm either admits a supply of air to the delivery connections and cuts olil the exhaust therefrom, or it opens the exhaust and cuts off the supply.

Now the control of diaphragm 27 by chamber 31 is brought about by holding compressed air in said chamber to open valve 24 and close 'exhaust 32 or by allowing air to escape from said chamber and thus leave valve 24 closed, or free to close, and said exhaust open. For this purpose a restricted supply leads from supply pipe 10 to Chamber 31 and a more rapid exhaust extends from said chamber to the atmosphere. The former of'these may be traced from pipe 10 through recess 12, passages 33, 34 and 35 to chamber 31, and the latter from chamber 31 through passages 36, 37 and 38 to atmosphere. Passages 35 and 36 are found in opposite sides of cap 29', passages 33, 34 and 37 in the portion 13 of the body -of the instrument, and passage 38 in a nipple 39 screwed into a threaded opening in the upper portion of tace of the instrument body. A restricting valve 40 is interposed between the passages 33 and 34 and when in set position allows a small amount of compressed air to leak through into chamber 31. The valve 40 is screw-threaded into a threaded opening 41 formed in a projection 42 of the body portion 13. The valve 40 is provided with a kerl 43 and may be readily set by a screw-driver or other suitable tool passed into the opening 41. A cap screw 44 screwed into the same opening 41 prevents interference with the position of the restricting screw 40. The diaphragm 27 is, of course, provided with two openings, one in line with passages 34 and 35 and the other in line with passages 36 and 37. The exhaust opening through passages 36, 37 and 38 is ot larger minimum capacity than the supply opening about the restricting valvev 40. Consequently, when exhaust portl or passage 38 is closed, air under pressure will accumulate in chamber 31 and move diaphragm 27 to close exhaust port 32 and open supply valve 24. On the other hand, when port 38 is open, the air in chamber 31 will escape more rapidly than it can enter around the valve 40 and so supply valve 24 will be closed and exhaust port 32 opened. The proportion and arrangement of parts is such that the diaphragm, when moving under the accumulation of pressure in chamber 31, engages port 32 before it engages valve 24 and thus closes the former before opening the latter. ln its movement in the opposite direction, the diaphragm allows valve 24 to close before it opens exhaust port 32.

1n order to control. the opening and closingot port 38, an. atmospherically responsive element is provided. This may be the thermostatic element of Figs. 1, 2, 3 and 6, or the hygrometric element of F ig. 5. The thermostatic element, designated 45, is composed 0f two strips et metal having different coeliicients of expansion, as, for examlple, an inner strip 46 of iro-n and an outer strip 47 of brass. yThese are secured together throughout their. length and the composite strip is bent back upon itself near its lower end and secured t0 the center of the weighted saddle block 48. The upper end ot' the element 45 has an additional strip 49 secured to it and this strip is oli'set so as to form a. pocket for the valve seat 50 which is preferably a` small sheet of Celluloid which cooperates with the pointed end of the nipple 39 through which the exhaust passage 38 extends. The latter terminates in asmall port as shown. This, however, as before noted,vis large enough in cross sectional area to allow air to escape faster than it can enter around restricting valve 40. To allow the seat 5() to fit the port well, the strips 46,47 and 49 are apertured as illustrated.'

The saddle block 48 has its depending portions retained yby pivots 5l threaded through threaded openings in lugs 52 extending torward from the trame portion 53 of the instrument. The lugs 52are slotted so as to exert a resilient clamping action upon the pivot screws 51. A leaf spring 54 is secured at one end to a horizontal member of the frame portion 53. The tree end of this spring is formed with a hump which coacts with an angular projection 55 on the saddle 48. When the arts are in the position illustrated, the sprlng bears against the rear of the projection 55 and holds the saddle yieldingly a ainst the end of the adjusting screw 56. WIien the upper end of the thermostatic strip 45 is dra-wn outward a considerable distance by hand, then the forward side of the projection 55 engages the top of the spring 54 and the latter yieldingly holds the strip away from nipple 39 in its outwardly extending position. The spring 54, by pressing the weightedl saddle 48 against the top ofscrew 56, augmente the action of the weight of the saddle.

For adjusting the position of screw 56 and indicating its adjustment, an arcuate dial 57 is provided. This dial is secured to theouter end of an arm 58 having an eX teriorly and inter-iorly threaded hub 59'. The exterior thread on the hub engages the threads of a threaded opening in the horizontal member of the frame 53. The interior thread ot' the hub 59 is engaged by the threads of the adjusting screw 56. IVith this arrangement it will be seen that screw 56 will be slightly raised and lowered by moving dial 57 back and forth.' Its movemeritv rota-tes hub 59 and causes it to screw into or out of the threaded opening in the frame and thus to raise or lower screw 56 by a slight amount. A resilient catch 60 is fixed at one end t0 the Jframe 53 and its free end is adapted to pass into notches 61 formed in the upper ed e of the dial 57. Suitable legends, as Co d, Medm, and Hot on the face ot' the dial indicate the results which follow a shifting of the dial which brings the catch, and pointer, 60 adjacent these words.

Then the instrument is provided with a hygrometric element. it may be constructed as illustrated in Fig. 5. There a singleI .metal strip 6:2 carries the valve at its top.

It is bent laterally at its lower end so `as to provide a horizontal ortion 63 which is secured to the under si e ot the saddle 48. A bracket 64 secured yto the inner face ofthe strip 62 forms an abutment .for the hygrometrie element 63El which in thejpresent case is a small cylinder of wood cut crosswise ot the grain. It is provided with a metal cap at each end. A screw 65 extends through a counter-sunk hole in bracket 64 into threaded engagement with the upper cap 66. Similarlyv a screw 67 is screwed into the lower cap 68 through an openin in ythe arm 69. The latter is firmly held etween the end ot the cap 68 and the square shoulder of the head ot' the. screw 67 which extends through an opening in the adjacent portion Ot the portion 63 otI the strip 62. The rear end ot the larm 69 bears against the top of the adjusting screw 56. Varying the position of the screw 56 tends to move the upper free end ot' the strip 62 toward or from the nipple 39 and thus varying the pressure upon the latter exerted b v the strip or actually displacing the strip relatively to the nipple. Expansion or contraction of the elements 63a slightly opens and closes the port 38 and brings aboutthe required control of the diaphragm as previously vdescribed. In the case'ot' the hygrometric conltrol, the dial, ot course, is ditl'erently marked than when the cont-rol is a temperature control. Thus` lVet and Dry replace Cold and Hot.

Obviously, although air under pressure is commonly employed in instruments ofthe k-ind herein described for the purpose of supplying the working force and controlling the diaphragm, vet gases ot various vkinds might be used for this purpose. For convenience, however, I have used the term air in the claims as generically representative of such equivalents.

That-I claim as new and desire to secure by Letters Patent of the United States is:

1. An atmospherically responsive device comprising structural parts providing an air supply passageand an air delivery passage connected by an intermediate opening and having an exhaust passage connecting said deliver)y passage to the atmosphere, a valve for controlling said intermediate opening, a diaphragm positioned adjacent to said valvel and said exhaust passage and operative to directly engage said valve and the port of said exhaust "passage to open said valve and close said port. means for supplying and exhausting air under pressure to operate said diaphragm, and means responsive to atmospheric changes to 'control said supplying and exhausting means.

2. An atmospherically responsive device comprising structural parts providing air supply and deliverv passages connected bv an intermediate opening. and an exhaust passage leading from said delivery passage to the atmosphere; a valve tor opening and closing said intermediate opening: a spring tending to close said valve; a diaphragm scoured dat its ,periphery and free near its center to directly engage both said valve and the port of said exhaust passage, in the former ease to Coperate with said spring to open and elose'said valve*` and in the latter ease to eoperate with said exhaust port to Close and open said exhaust passage; means for supplying and exhausting air under pressure to operate said diaphragm; and means responsive to changes in atinospherie conditions to eontrol said air supply ing and exhausting nieans.

3. .Xn atn'iospherieally responsive device comprising structural parts providing inain air supply and delivery passages and. a inaiu exhaust passage leading troni said delivery passage to the atmosphere; a wall between said inain supply and delivery passages hav ing an opening provided with a valve seat on the supply passage side ot said opening: a valve eoperating with said seat and having a stein extending through said inter mediate opening; a spring acting hetween said stein and wall to seat said valve when Lassen@ unrestrained; a diaphragm on the delivery passage side of said valve. fixed at its periphery and having its center in position to engage said stein to aetuate said valve in opposition to said spring and to close the delivery passage end o't' said exhaust passage when said diaphragm is in engagement with said valve stein: said structural parts forming also an auxiliary chamber on the opposite side ot' said diaphragm from said valve. eonneeted with .said supply passage hy a restricted passage and to atmosphere hy an auxiliary exhaust opening having a larger niiniinuin cross-sectional area than .said restrieted passage, and an atmospherieally responsive element for opening andV elosing said auxiliary exhaust opening in response to atmospheric changes.

in testimony whereof have hereunto set iny hand this wth day of August, i). lflli.

NICLS HUFSTD 

